Balancing mechanism for pressure logs



Jan. 8, 1952 E. M. GSTERMAN BALANCING MECHANISM FOR PRESSURE LOGS FiledMarch 21, "1959 B Y; 5; MEL,

Patented Jan. 8, 1952 BALANCING MECHANISM FOR PRESSURE LOGS EdvinManritz fisterman, Stockholm, Sweden, assignmto Svenska AckumulatorAktiebolaget Jungner, Stockholm, Sweden, a corporation of SwedenApplication March 21, 1949, Serial No. 82,518 In Sweden April 10, 1948 2Claims.

In pressure logs, in which the pressure of speed is balanced by aid of aspring device, the balance mechanism usually comprises a lever which isactuated by a moment deriving from the pressure of speed. The springdelivering said moment has been arranged so that its one end actuatesthe balancing beam whereas its other end has been rotatably secured to atransferring arm. The position of this arm is determined by the positionof a cam which is adjusted by an auxiliary motor. The latter is in turncontrolled by a contact device which is actuated by the turn of thebalancing beam. The transferring arm has been constructed as adoublearmed lever and journalled at a point near the end of thebalancing beam, which carries the attachment of the balancing spring.This arrangement is considerably simplified by the present inventionwhich substantially involves that the transferring arm is constructed asa singlearmed lever. Suitably the transferring lever is journalledconcentrically with the balancing beam. This brings the advantage thatthe elements become simpler in manufacture and that the requirement forspace is materially reduced without giving up the accuracy.

An embodiment of the invention is illustrated in the accompanyingdrawing in which Fig. 1 is a diagrammatical view of the arrangement,partly in perspective, and Fig. 2 is a longitudinal partial sectionthrough the balancing spring.

In the drawing I designates a pressure rod which transfers the forcederiving from the pressure of speed. This force is approximatelyproportional to the square of the speed of the vessel. The pressure rodengages a projection II on a balancing beam l2 by edge means H, the beambeing journalled by an antifriction bearing such as a ball bearing I6 ona shaft or stem [8. The balancing beam carries a rotatably journalledspring attachment 20 and a slip contact lever 22. Journalled on theshaft 18 is also a transferring arm or lever 24 which is U-shaped andhas its shanks located at opposite sides of beam [2. At its end thelever 24 carries ball bearings 26, 26 which in turn carry an attachment28 for spring means such as one end of a helical spring 30, the otherend of which is connected with the spring attachment 20. The force fromthe spring 30 can be controlled by a screw 32 engaging the inner side ofthe spring 30 and a nut 34 engaging a screw-threaded sleeve 36 which inturn engages the spring at the outer side thereof. The screw 32substantially being adapted to change the number of free turns of thehelical spring 30 whereby the spring coefiicient of the latter ischanged. The nut 34 and sleeve 36 are adapted to change the tension ofthe spring 30, by rotation of nut 34 relative to sleeve 36 and axialdisplacement of the latter as a result of such rotation. The attachment28 further comprises a ring 38 surrounding the sleeve 36 and engaged bythe end surface of the nut 34, said ring having opposite studs 40, 40carried into the bearings 26, 26. The arm or lever 24 comprises a roller42 mounted at one shank thereof and suitably formed as a ball bearing. Acam 44 keyed to a rotatable shaft 46 actuates or engages the roller 42and it is to be noted that the point at which the arm 24 is thusactuated is located at the same side of the axis of shaft [8 as theplace of the arm 24 where the spring 30 actuates said arm by way of thespring attachment so that the arm 24 will act as a single-armed lever,the pivot of which is formed by the shaft 18.

Mounted on the shaft 46 of the cam 44 is a worm gear 48 which mesheswith a worm screw 50 keyed to a rotary shaft 52 which is carried bybearings 54, 54. The shaft 52 is driven by an electric motor 56 by wayof a gear transmission 58. A contact device 60 operated by the contactlever 22 on the balancing beam [2 is coupled by a phase changingcoupling arrangement to the motor, which is shown as a phase split motorhaving two windings 56a, 56b. The contact device 60 may have two or morepair of contacts mounted symmetrically and is shown with four contacts60a, 60b, 60c, 6011 connected by leads 62a, 62b. 62c and 62d,respectively, to points 64a, 64b, 64c and 64d, respectively, arrangedsymmetrically relatively to a central point 65 of a resistance 66, theends of which are connected to a source of alternating current 68 byleads l0, 12. The central point 65 is connected to one terminal of thewinding 56a by a lead I4 including a condenser 16, the other terminalbeing connected by a lead 18 to the contact lever 22. The terminals ofthe winding 56b are connected to the leads l0, 12 by leads and 82,respectively. The operation of the coupling arrangement would beself-explanatory, and it would be sufiicient to state that the motordoes not move, when the contact lever 22 engages the two centralcontacts 60b, 60c, rotates in one direction if the lever 22 is displacedto one side from its central position and rotates in the oppositedirection if the lever is displaced to the other side from the centralposition. The direction of rotation is chosen so that if the turningmoment actuating the balancing beam 12 and deriving from the pressure 3of speed is greater than the turning moment on the balancing leverderiving from the spring 30, the moment in both cases being taken withrespect to the axis of shaft l8, the transferring lever 24 turnscounterclockwisein the drawing about theshaft i8 whereby the moment fromspringsfl is increased. The moment is approximately proportional to thesquare of the angular change of the.

lever 24 from the zero position. The peripheral contour of the cam 44 isapproximately an Archimedian spiral.

The cam 44 is connected with. a transmission. device 84, for example,an;elex-itric transmission device and a pointer 85 cooperating, with ascale 88, the connection being obtained by a gear transmission 90. Theturning movement of the pointer ment to said balancing beam proportionalto the 86 may be transmitted by the' transmissionrdevice 84 to anydesired number of points in the vessel, in which the log is mounted. Therotary rnoye ment of the cam M as well as that of the worm screw 58 andthe pointer 86. become proportionate to the speed, i. e. the scale ofspeed becomes rectilinear.

By the fact that the roller 32 is located on the transferring lever 24,this lever. becomes single-armed. and gets a simpler form. thanv in the,prior device. At the sametime a great difference between the maximumradius, and the minimum radius of the cam 54 can be. obtained whileutilizing only a relatively little space.

What I claim is: v

1,. A balancing mechanism for pressure logs, comprising a shaft, abalancing beam rotatable about the. axis of saidshaft, means to, imparta turning moment proportional to the pressure of speed to be measured bythe log to said balancing beam, a transferring arm, mounted. rotatablyin pressure of speed. to be measured by the log, a

transferring arm pivoted on said pivot shaft extending-coincident withand beyond the end of saidbalancing beam, a spring connected betweenthe. end of the balancing beam and the end of the transferring arm, arotatable cam engaging said transferring, arm, between said pivot shaftandthe end connected to thespring, a motor for rotationofsaid cam andaswitch controlling said motoractuated by motion of said balancing beam.

EDVIN MAURITZ GSTERMAN.

REFERENCES. CITED The following references; are of recordiin the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,968,539; Rydberg July 31, 19342,167,976 Blasig Feb. 8, 1 9 8 2,403,685.: Rosenberger Oct. 1, 19462,409,435 Ketay etal Oct. 15, 1946

